Water may contain many different kinds of contaminants including, for example, particulates, harmful chemicals, and microbiological organisms, such as bacteria, parasites, protozoa, and viruses. In a variety of circumstances, these contaminants must be removed before the water can be used. Harmful contaminants often need to be removed from water using a first treatment material before it is potable, i.e., fit to consume.
Beyond containing harmful contaminants, both treated and untreated drinking water often has a less than ideal taste. There are several factors which may adversely affect the taste of water, including, but not limited to, pH, hardness/softness, post-filter bacteria growth, alkalinity, mineral content, organic contents, etc. These factors are often affected by the first treatment material used to remove the contaminants in the water.
A second treatment material may be used in conjunction with the first treatment material. The use of a second treatment material often decreases the output of the water treatment cartridge. Use of a second treatment material often equates to a more complicated flow path, an additional dense bed for the water to travel through, the use of a permeable and semi-permeable membranes between the first and second treatment material, the use of retainers for collecting fines and sediment, etc.